Dental chair



. dental chair embodying my invention.

' UNITED- *STATES PATENT OFFICE..vr c

' LEvI srUcH,v or HART, MICHIGAN, A'ssIGNoH 'ro H. D. JUsri, oE g ,y

f y PHILADELPHIA, PENNSYLVANIA.

j DENTAL CHAIR.

SPECIFICATION forming par; of Letters Patent No. 381,040, dated'A'prii 1ol 1888.

Application tiled Nlovember 2. 1887. Serial No. 254,054. (No model.)

of improvements in dental chairs, as herein s et i'orth and claimed;I

Figure l represents a partial side elevation and partial vertical section of a portion of a Fig. 2 represents a horizontal sect-ion on line x x,.Fi g. 1,on an enlarged scale. Fig. 3 represent-s ahorizontal section on line g/Ly, Fig. l, on an enlarged scale. Fig; 4. represents a vvertical section on line z z, Fig. 2, Fig. 5 represents a lvertical section'on line z z', Fig. 3.- Fig. 6

represents aside elevation ot' a detached portion.

v Similar letters of reference indicate correbarbers or other chair.

. pressedv serves to elevate the annulns.A `Thel B represents a stem or standard which is secured to and depends frointheseat Aand enters a casing, @which may be of cylindrical or other form. Y

Freely encircling the standard B is an annulus, D, which is locatednear the top thereof,

and has at one portion 'of its periphery a lip, E, which rests in a recess lor Vgroove ofthe cross-bar F, the latter extending horizontally within the casing Gand being secured, thereto. Pivoted -to the annulns opposite to the lip E is a rod, G, which passes to the bottom of they casing, where it is4 pivoted to or freely connected with a pedal or foot-lever, H, which is,

accessible outside of the casing, and when dey rests on 4a crossbar, L, the latter extending horizontally within the casing C and being secured thereto and being substantially parallel tothe bar F. The inner periphery of said annulns K istoothed, as at K', soY as to'bit'e said standard B. 'Bearingiagainst the under W' 55 sideot lsaidannulus K,or pivoted thereto, is a link, M, to which is pivoted a pedal or handlever,-N,-w`hich has its bearingson the casing;

C andi is accessible outside of the same.y

,Connected with the pedal H andbase of the 'l casing is a spring, P. Connected Wit-h the annulns K and jbase ofthe casing is a spring, Q,

said springs exerting downward pressure .on

the annuli D'andK and,V serving to restore thek same to their normal positions. f The inner periphery ofthe annulns D isfaeed with 'steel blocks J, so'as to takeiirmhold of the stand.- ,ard, the body Vofy said annulns being brass, castiron, or other metal. The annulns K is preferably formedentirely of steel.

- LIThe standard B is guided bythe top cap of 7.o

to the bottom of said standard and freely itte'd on an upright rod, T, which "is secured tothe base of the easing and/the cross-bar F,lwhere by said eye slides on said rod in the ascending and descending motions ofthe standard.l

The operationy is as follows:r When the seat is to be raised, the lever N is depressed,where by one side of the'an'nulus K israised andthe teeth K at said side bite the standardkB. The ascending annulns thus carries the standard with it until the desired heightis obtained,.

when the lever is let go, and the annulsthen dropstoits normal position on the cross-bar L. The standard now being free ofthe annulus/K is caught bythe annulns D, which, as

has been stated, is supported on one side by the cross-bar F and forced down on the oppopos'ite side by the spring P, the .annulns assuming an oblique position downward, so `that the teeth J bite the standard and thereby pre; vent descent of the same, the seat thus being held in its elevated position. When the seat n .the casing C and an eye','S, which is secured Yis to .be lowered, the pedalHis depressed,

whereby the annulns is raised and brought to a horizontal or approximatelyhorizontal position, whereby the rteeth J are withdrawn from l the standard,- and the latter then drops and kthe seat returns to its normal position.

. ".The' extent of elevation of 'theseat is regu, .19e

lated or adjusted by thev lever Nboth in the throw of the same and the number of times said lever is worked. Y

The casing C iucloses the annuli or clutches D and K and other parts of the device, also providing bearings for the levers H N and forming a proper finish for the chair below the seat thereof.

I am aware that it is not new to construct a lifting device wherein an annulus is operated by means of a pivoted lever so as to raise a rod, the device having also a second annulus operated by gravity for holding the said rod in place, the said secondannulus being released from the rod by means of a second rod operated by a treadle and adapted to be brought in contact with the said second annulus, raising the side thereof which engages with the lifting-rod, and such I do not claim; but Iam not aware that the construction as herein shown and described is old-that is, the holding-annulus having a lip resting in a notch in a crossbar of the casing and the opposite side ofthe said annulus being pivoted to the operatingrod, whereby the operation is reliably and certainly eected without jar or shock.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A dental chair having a seat with a depending standard, a casing in the top opening of which said standard is inserted, the crossbar F, secured to and within said casing, the annulus D,surrounding said standard and having a lip, E, resting on said cross-bar F, and also having its inner periphery inclined, the

rod G, pivoted to the side of the annulus D opposite to the lip Efthe treadle projecting through an opening in the casing C and having its inner end secured to the lower end of rod G, and the spring P, secured to the inner arm of said treadle and to the base, said parts being combined substantially as and for the purpose set forth.

2. A dental chair having a seat with depending standard, a case in which said standard is inserted, a recessed cross-bar within said casing,.anannulus surrounding said standard and having a lip resting in the recess of said crossbar, the inner periphery of said annulus being inclined, a rod pivotally attached to the side of the annulus opposite from the lip, and a treadle connected with said rod, said'parts being combined substantially as and for the purpose set forth.

3. A dental chair having a seat with standard and a casing iu which said standard is inserted, the cross-bar F, the annulus D, with lip E and inclined inner periphery, the rod G, pivotally attached to said annulus at the side opposite the said lip, the treadle H, connected with said rod G, the cross-bar L, the annulus K, with teeth K on one side of the inner periphery, the link M, secured to said an nulus K on the same side thereof as the teeth K', and the lever N, with spring Q, said parts being combined substantially as and for the purpose set forth.

. LEVI STCK. Witnesses:

JOHN A. WIEDERsHEIM, A. P. J ENNINGs. 

